The present invention relates generally to a method for functional testing of a lateral-acceleration sensor in a vehicle equipped with a dynamic stability control system.
DE 199 36 596 C1 generally describes the functional testing of a dynamic stability control sensor system comprising a yaw-rate sensor, a lateral-acceleration sensor and/or a steering-angle sensor during a vehicle test drive that includes driving at specified longitudinal velocity on a curve. For this purpose, the values of the measured signals being received from the dynamic stability control sensor system at the beginning of a test process are recorded as the starting values. During the test drive of the vehicle, which takes place under specified conditions, the values of the measured signals being delivered continuously by the dynamic stability control electronics are compared with the associated starting values. In particular, these are the values delivered while the vehicle is being driven on the curve at a longitudinal velocity within a predetermined velocity range. For such driving conditions, the measured signals of the sensors in question are within characteristic ranges in the error-free case. From subsequent evaluation of the results of the measured signals delivered during the test drive compared with the associated starting values, it is possible to determine whether the dynamic stability control sensor system is functioning without errors.
The method according to DE 199 36 596 C1, therefore, requires that the vehicle be driven on a curve under specified conditions. This is problematic if the test must be performed as an inspection at the end of the assembly line, that is, promptly after completion of the vehicle on the assembly line. The manufacturing facilities themselves often lack the space needed for driving on a curve, and disadvantages are also associated with specifying driving maneuvers in the proving ground. Varying weather conditions sometimes cause low coefficients of friction, due to ice and snow, for example, leading to vehicle instabilities which, in turn, falsify the measured result of driving on a curve, and thus cause incorrect detection of errors. This can lead to problems in the course of series production, because the manufacturing process is then delayed, causing additional costs. Allowance for such effects could be made by broadening error margins, but the detection capability would be undesirably reduced.
Accordingly, it is desired to provide a method for functional testing of a lateral-acceleration sensor in a vehicle equipped with a dynamic stability control system that improves over prior art approaches.